1. Field of Invention
This invention relates to the field of marine vessels and particularly to a vessel construction which is capable of withstanding the force of an underwater explosion without sustaining structural damage or damage to personnel and sensitive machinery.
2. Description of the Prior Art
In the hull structure art designed to absorb the force of underwater explosions, armament type equipment has been carried externally of the hull for this purpose. For example, in Almengual U.S. Pat. No. 1,236,033, a series of chains and springs, and possibly rubber, are mounted external of the hull to absorb forces which would otherwise damage the hull proper. In Pagenstecher U.S. Pat. No. 43,377, a plurality of rubber bags which are filled with water surround the vessel hull to absorb explosive forces. Brown U.S. Pat. No. 2,969,036 teaches the use of a liquid filled flexible outer skin external of the hull to absorb the impact of underwater explosions. It will be noted that in this type of prior art, additional armament or equipment is carried external of the vessel's hull to absorb the force of underwater explosions and other forces which would otherwise potentially damage the vessel's rigid hull. This extra equipment, including the chains, the water bags and the like, is extremely heavy and adversely affects the hydrodynamic characteristics of the vessel, its speed potential and its maneuverability potential and therefore is undesirable.
To overcome these disadvantages, it has been conventional practice to fabricate ship hulls of very heavy, relatively inflexible, thick, metal plate material. These thick plate members are capable of partially absorbing the force of an underwater explosion by absorbing the energy thereof through a bending process, however, this extraordinarily thick plate hull construction, which is necessary to absorb the energy of underwater explosion, is untenable from a weight standpoint in that the speed capability and maneuvering capability of the vessel are adversely affected thereby.